We are delighted to feature another guest blog today. Rory McLeod works as Development Officer for Glasgow & Clyde Valley Green Network, and leads on the delivery of the grassland and wetland workstreams contained within GCVGN’s Green Network Blueprint.
Introduction
Glasgow & Clyde Valley Green Network (GCVGN) were delighted to recently launch our new Clyde Grasslands initiative that seeks to reverse the decline of grasslands and meadows across the Glasgow City Region. Supporting the launch was a new study, Mapping Species Rich Grassland Networks, which we hope will act as a catalyst for action and a framework for delivery. The work was led by GCVGN on behalf of partners Plantlife Scotland, Butterfly Conservation, Bumblebee Conservation Trust, and funded through NatureScot’s Nature Restoration Fund (NRF) development stream.
The study sought to identify remaining species rich grassland habitat, map their associated dispersal networks, identify opportunity areas for future restoration and expansion, and finally, to map grassland Nature Networks to target future work.
The work was carried out on our behalf by SAC Consulting, and we are now using the study outputs to work with local authority, NGO and utility provider partners to develop a programme of work planned within a framework that will maximise grassland habitat connectivity across our region.
This blog will describe the importance of grasslands in a regional context, the development of the Clyde Grasslands initiative, the methodology and findings from our report, and our future ambitions.
The importance of restoring grasslands in the Glasgow City Region
The pressing need we have to restore species rich grasslands for nature, people and climate will be well known to regular readers of this blog. The wider trend that has seen 97% of species rich grasslands lost in the UK since the 1940s, (Hooftman and Bullock – 2012) has been mirrored within the eight Local Authorities that make up the Glasgow City Region (GCR). This is a diverse area of over 330,000 hectares, that contains both Scotland’s largest continuous urban area, but also significant rural areas of lowland farming and upland sheep grazing. As such, the GCR has been highly vulnerable to changing land uses such as the intensification of agriculture and urban expansion, with only remnants of species rich grassland now remaining.
We have a good understanding of the benefits restoring grassland habitats across our region will bring. For wildlife, it will create habitat for a large number of species, both flora and fauna, including plants, fungi, invertebrates and birds. Pollinators are a particular focus for our project, and with 84% of all EU crops dependent on pollination, (Klein et al., 2007), species rich grasslands are a vital pollinator resource. To focus on just one type of pollinator, butterflies, Butterfly Conservation have advised we could reasonably expect a number of species to benefit and spread in our region as a result of the delivery phase; including three species of Skipper, Small Copper, and Common Blue.
A less known benefit of grasslands until relatively recently has been their capacity to sequester and store carbon. With up to 30% of the earth’s carbon stored in grassland carbon sinks, grasslands are every bit as important as forests and other ecosystems in the fight against greenhouse gases. A recent Plantlife study has sought to deepen our understanding of this relationship, and points to evidence that increased species-richness in grasslands increases carbon sequestration. Whilst soil carbon markets are still emerging, and some research gaps remain to quantify grasslands’ carbon storage and sequestration ability, the potential for grasslands to play a significant role in the City Region’s future drive for Net Zero seems clear.
The need for the Clyde Grasslands study
In 2019 GCVGN published a Green Network Blueprint for Glasgow City Region. At its core was an ambition to restore, enhance and connect habitat networks strategically across the region, with neutral grassland a key habitat type. Habitat or nature networks are critical to ensure grasslands are not created in a piecemeal, ‘opportunistic’ way, but rather as part of a larger coherent network. Ensuring functional connectivity between grassland habitats is critical for pollinator species to be able to move through the landscape to forage, breed, disperse or migrate.
Whilst the Blueprint identified some spatial priorities for neutral grassland, the data was ultimately not comprehensive enough to provide a framework that would allow the targeting of effort to best effect. The Clyde Grasslands study sought to fill this knowledge gap, building on previous analysis and understanding, and providing a robust evidence base to target limited resources for the best outcomes.
Project methodology
The Clyde Grasslands study made three significant changes to our earlier Blueprint methodology: – the types of grassland habitats included; the dispersal distances used to model pollinator movement through the landscape; and the approach to data collation.
The first was to broaden the range of species rich grasslands we considered. Whereas previous studies modelled solely neutral grasslands, we expanded our focus to include the four species rich grassland types identified by NatureScot guidance – acid, neutral, wet, and calcareous.
Secondly, we revisited the dispersal distances used in the GIS based “least cost modelling” which underpins the analysis and outputs. “Least cost modelling” estimates how permeable or impermeable different land cover is for a chosen “focal species” to move through. This creates an “intelligent buffer” or network around habitat patches indicating how far species can move through the landscape, and how connected the networks are.
The Blueprint was based on a 300m dispersal distance for a generic neutral grassland focal species. The Clyde Grasslands Study used two dispersal distances: 300m was used once again to maintain consistency with the original work, but applied to the wider range of grassland types. 300m represents the lower dispersal capabilities of some grassland species such as solitary bee. We also used 800m to reflect wider dispersal capabilities for more mobile species such as the carder bumblebee.
Finally, we took a much wider approach to data collation. The original Blueprint work drew solely on existing habitat records, some of which were 30 years or more old. This time we combined grassland plant and butterfly indicator records from BSBI, Plantlife and Butterfly Conservation, with the habitat data to act as a first line of verification that the grassland still existed, and as a proxy for quality. We then drew upon the wealth of local knowledge that exists across the region, and tested draft outputs for each local authority area with local experts. This identified errors, omissions and provided qualitative information.
For a fuller account of the GIS methodology we would recommend reading the detailed Clyde Grasslands report produced by SAC Consulting for our project, which can be found here
Summary of outputs and findings
The outputs identified over 1,800 habitat patches with strong potential to be species rich grassland. These were typically small, fragmented habitats, with over 67% less than two hectares in size. As expected, larger patches tended to exist in upland areas with less intensive agriculture and development.
The outputs also identified over 400 “opportunity areas” where the targeting of new habitat creation could potentially connect currently fragmented habitat networks. Given our 2019 Blueprint identified 92 neutral grassland opportunities, we were delighted with this outcome! It provides us with a much broader framework from which to develop project work, across a much more diverse range of opportunity types spanning urban, peri-urban, lowland rural and upland rural situations.
However, given the decimation of species rich grasslands in our region post-WWII, unsurprisingly the report also flagged a number of concerns. Habitat patches in our region remain largely small, particularly in urban and per-urban situations, isolated, and fragmented. Habitat networks based on species with higher dispersal abilities were, as expected, better connected, however even these networks were still highly fragmented. This means that species which depend on these habitats remain vulnerable, particularly those with lower dispersal capabilities, and in urban areas where buildings and roads are barriers to movement. This report finding makes an early focus on habitat creation in built up urban/peri urban areas essential, and helped to shape our approach outlined in next steps below.
If there is a primary concern identified in the report, it is the lack of high-quality spatial datasets. Remote sensing techniques are still insufficient to accurately identify grasslands which are trickier than other habitats, such as the tree cover in woodland. This means as technological advances continue to be made, – whether remote sensing, the use of drones, or AI bio-acoustics, ground-truthing in the field remains vital. The difficulties associated with the mapping of species rich grasslands has often meant they have received less consideration in decision-making processes than other habitats, and this continues to make them vulnerable to a wide range of developments today, including tree planting targets!
Next steps… Grassland Nature Networks
As mentioned at the outset, there is a very wide range of land uses in the GCR, and the reality is that some of the opportunities identified in our study will be easier to deliver than others. Rural, privately owned land currently has no obvious mechanism or incentivisation for delivering at scale. We hope the emerging Agriculture and Rural Communities Bill will start to address this.
With council bodies across Scotland tasked to deliver “Nature Networks” under the new National Planning Framework,we have been working closely with the eight City Region local authorities to produce a regional approach to Nature Networks. This has highlighted the scale of the task they face, and also where some early opportunities lie. Our initial programme of work will therefore focus largely on urban and publicly-owned land, and we are working with local authority partners to explore options on land they either own or manage. This has involved an analysis of our study outputs (habitat networks and opportunity areas) in the context of a range of other data, such as green space, open space audits, golf courses, protected sites, the NHS Estate and utilities, to develop a regional framework for Grassland Nature Networks.
We have been guided in this process by the concept of habitat corridors and ‘stepping stones’, which are one of five key elements of a Nature Network (Lawton, et al. 2010), as well as Buglife’s approach to developing BLines, (3km-wide pollinator corridors mapped across the UK). Our work has focused on what grassland Nature Networks would look like in a more granular, regional context, using the study outputs and local expertise to develop a connectivity framework, based on 600m wide corridors (twice the minimum dispersal distance used in the study). Discussion with local authority colleagues has been key to this work, ensuring the identified Nature Networks are aspirational but realistic. Working at a regional level it is also critical that cross-boundary connections are identified and link up. From this work we are currently developing a suite of potential projects in council-owned greenspaces that would contribute to the identified Grassland Nature Networks.
We hope this approach will form the basis of a future funding bid, while also providing a rationale for public landowners and managers to target their own resources towards delivery on these sites. The scale of the ambition for Clyde Grasslands means that it is a long-term project, however, action is needed now. We intend to drive forward those opportunities most easily deliverable in the short-term, while planning for longer-term opportunities as new delivery mechanisms emerge in the future.
Final thoughts
One area of concern that we feel it is important to highlight is overall delivery capacity, both for GCVGN (two FT members of staff) and also for our local authority partners. The outputs from our study have been enthusiastically received with a high level of engagement, and we also feel confident we will be able to identify an extensive and realistic suite of delivery projects from our analysis. However, with many local authorities significantly depleted in terms of staff resource and expertise, capacity is limited.
Although currently receiving a ring-fenced allocation of NRF funding, we have encountered local authorities with funds to spend but not necessarily the means to spend them. Others have employed private sector contractors to help with delivery work, but report these contractors are becoming oversubscribed from demand. We raise this as a point of concern which could have a significant impact on our collective regional (and national) ability to deliver the Nature Networks we all want to see happen.
Thanks!
We would like to thank our steering group members, Gill Perkins, (Bumblebee Conservation Trust), Phil Sterling & Julie Stubbs, (Butterfly Conservation), and Alistair Whyte, (Plantlife Scotland), for the time they invested to help develop this project.
We are hugely grateful to Dave Lang (NatureScot), Scott Shanks (RSPB Scotland), and Anthony McCluskey (Butterfly Conservation) for their input, and to colleagues in the eight Glasgow City Region local authorities whose generous allocation of their time has been invaluable.
We would also like to thank Dr Lorna Cole and the SAC Consulting team for their technical expertise and enthusiasm.
Lastly we would like to thank NatureScot for their Nature Restoration Fund Development funding!
The full Clyde Grasslands report can be found here
Scottish pollinators 